In a broad range of fields of physics and chemistry, research based on sample analysis is an essential and important process. It is an especially critical process in biology, particularly in the research of pharmaceuticals and diagnostic medicines for both humans and animals. To analyze a sample, it is firstly required “to break-up” and then “to homogenize” the sample. Especially in a case of a biological sample, when it is used for extracting protein or preparing RNA, DNA for PCR analysis, it is required to break-up its structural base, such as cell membrane, cell wall and the like, physically (mechanically) or chemically. The term “to break-up” used herein implies “to destroy tissue and/or cells of a sample physically (mechanically)”, and the term “to homogenize” implies “to destroy tissue and/or cells of a sample physically (mechanically), and then to add a buffer solution to the resultant substance in a suitable manner so as to produce a suspension thereof”.
A conventional breaking-up method includes those using such instruments as a potter-type homogenizer (see, for example, “Comprehensive equipment catalog for research and development 70000, 2001→2003” Asone Co., Ltd, November 2001, p. 944”), a homogenizer of rotor-stator system (see, for example, “Comprehensive equipment catalog for research and development 70000, 2001→2003” Asone Co., Ltd, November 2001, p. 944”), and a ball mill (see, for example, “Comprehensive equipment catalog for research and development 70000, 2001→2003” Asone Co., Ltd, November 2001, p. 946”).
However, in the breaking-up methods as mentioned above, heat is generated, and the heat could modify the sample (could cause damage to characteristics inherent to the sample). Consequently, there is a risk that an analysis reflecting the action and structure in vivo could not be any more obtained (especially, polymer components, such as protein, nucleic acid and polysaccharide, are required to be homogenized in conditions free from possible modification caused by heat). Further, in the conventional breaking-up methods, if a number of samples is increased, the instruments used need to be cleaned to avoid mixing among the samples (since those homogenizers are expensive and thus not “disposable”, they have to be used multiple times, cleaning them after each use).
In addition, especially in the potter-type homogenizer and the rotor-stator system homogenizer, since their operations are carried out in an open system, there could be a fear of contamination of the surroundings.
On one hand, one conventional breaking-up method that can solve the problem of modification of the sample due to the generated heat and the problem of contamination of the surroundings has employed the QIA shredder manufactured by QIAGEN to break-up the sample (see, for example, “QIAGEN Product Guide 2004” QIAGEN Co., Ltd, 2003, p. 258”). This method is characterized in that a centrifugal force is used to press the sample against a filter in the QIA shredder to thereby force the sample to pass through the filter and to be broken-up.